Multiple alignment of the Transposase_21 domains of proteins of CACTA related transposons from diverse organisms. Typical plant CACTA transposon sequences from six Magnoliophyta were included in the alignment. In addition, eleven novel CACTA-related elements identified here were included: seven from Eumetazoa and four from Fungi. Shading indicates the level of conservation of each residue. Boxes with Roman numbers I to III indicate conserved motifs of the Transposase_21 domain in all organisms. Box marked with A indicates a Transposase_21 motif displayed only by Eumetazoa and Fungi proteins.